1. Field of the Invention
The present invention relates to the inter-vehicle distance control apparatus for controlling an inter-vehicle distance between a present vehicle equipped with this apparatus and a preceding vehicle by controlling operations of the present vehicle, and more particularly to an inter-vehicle distance control apparatus for preventing passengers in the present vehicle equipped with this apparatus from having a sense of discomfort about a deceleration occurring during the inter-vehicle distance control of the present vehicle.
2. Description of the Related Art
An inter-vehicle distance control apparatus for controlling the inter-vehicle distance between a present vehicle equipped with this apparatus and a preceding vehicle by controlling operations of the present vehicle is already known. Such an inter-vehicle distance control apparatus is typically configured to include: (a) a sensor for detecting a preceding vehicle; (b) a deceleration unit for decelerating the present vehicle; and (c) a controller for controlling the deceleration of the present vehicle by controlling the deceleration unit based on output signals from the sensor. See, for example, JP2002-79846A.
However, with such a conventional inter-vehicle distance control apparatus, passengers (especially, the driver) in the present vehicle equipped with such a conventional apparatus may have a sense of discomfort about a deceleration during the inter-vehicle distance control of the present vehicle in some circumstances.
For example, under the circumstance where the inter-vehicle distance is set relatively short under the inter-vehicle control, the passengers in the present vehicle equipped with such a conventional apparatus may have a sense of discomfort that the deceleration may be too gradual when the amount of undershoot becomes larger than necessary. On the other hand, under the circumstance where the inter-vehicle distance is set relatively long under the inter-vehicle control, the passengers in the present vehicle equipped with such a conventional apparatus may have a sense of discomfort that the deceleration may be too rapid when the amount of undershoot becomes smaller than necessary.
In addition, for example, under the circumstance where the inter-vehicle distance is relatively sufficient, the passengers in the present vehicle equipped with such a conventional apparatus may have a sense of discomfort that a deceleration gradient of the present vehicle may be larger than necessary when the deceleration is suddenly and rapidly increased to a target deceleration.
Furthermore, for example, under the circumstance where the inter-vehicle distance is relatively insufficient such as under a deceleration in following or under a deceleration in interruption, the passengers in the present vehicle equipped with such a conventional apparatus may have a sense of discomfort that the deceleration may be too gradual in light of such insufficiency of the inter-vehicle distance when the present vehicle decelerates with a small deceleration gradient as in the case where the inter-vehicle distance is relatively sufficient such as under a deceleration in catching-up.